1. Field of the Invention
This invention relates to an apparatus for attaching a watercraft to a piling, which attachment permits vertical movement of the moored watercraft due to changes in water level with respect to the piling. More specifically, this invention relates to a watercraft attachment which floats with the water level, rolls relatively freely around the piling and provides a bumper, or shock absorber, for the watercraft to piling interface. This invention is designed to function with very high reliability, that is without any mechanical parts that can be subject to the corrosive influence of ocean, lake or river water and to protect the watercraft from direct damaging impact with the piling.
2. Description of Related Art
Since man first built crafts to travel on the surface of the water, the problem of fixing the watercraft to a particular point has been addressed. In prehistory times, and to this day with small crafts, simply pulling the boat onto the land was the solution. However, with larger watercraft more elaborate solutions were and are needed. Where possible docks, piers and pilings are installed where the boats are to be moored. Such devices for fixing the boats are necessary for providing a means for embarking or disembarking. Fixed structures, such as docks, piers, or pilings, however, have certain limitations with respect to watercraft. Not the least of these limitations include the problem caused by the rising and falling of the water level and the damage that can be done to the watercraft by rubbing or impacting the dock, pier or piling. When the water level changes the relative location of the boat to the dock, pier or piling can change, permitting the boat to drift farther away or to be drawn in to the fixed structure. When a boat is drawn into a fixed structure, either by the change in water level, waves or even an impact from another watercraft, the impact and/or frictional rubbing can cause serious and significant damage to the boat. Many modern watercraft are made out of light weight materials, such as plastic, composites, and fiberglass. These, as well as boats with wood or metal hulls, are susceptible to damage from the impact with fixed mooring structures. This invention addresses this problem through the use of a floating tube, composed of a relatively flexible corrosion resistant material, which fits over and around a piling and to which a watercraft may be affixed. As the water level rises or falls the tube rises or falls, thereby maintaining the distance between the watercraft and the piling. When the watercraft is forced into the piling the shock absorbing characteristics of the tube protects the watercraft from damage. Moreover, when the watercraft is forced to rub back and forth against the piling, the tube acts as a frictional insulator by rotating around the piling with the watercraft, thereby protecting the watercraft from the frictional scraping with the fixed piling.
While this invention is novel in its simplicity and efficiency, it is by no means the only approach to the solution of this problem. Various other mechanical or structural approaches have been proposed.
One approach secures the watercraft through the use of beams with slidably attached arms which are clamped to the watercraft. The boat with rise and fall with the water level so long as the slidable attachment remains relatively friction free. No shock absorbing capability is provided because the boat is fixed horizontally in place by the attached arms. Energy imparted to the boat is absorbed either by the boat itself, the attachment point or the fixed arms.
Another approach involves the use of an elongate resiliently yielding member which is attached at one end to the floating object and at the other end at fixed mooring structure. The flexibility of the yielding member provides some capability to float with the water level and a fender can be attached to serve as a sort of protector to the floating object.
Another approach employs a spring attached at one end to the pier and at the other end to an arm having an attachment point for connecting on a boat to limit its movement relative to the pier or float. While this approach addresses some the problems associated with movement from waves or wind is does not appear to adequately address the rising and falling of the water level.
A further approach accomplishes vertical adjustment of the mooring via a pair of cables connected vertically between four dock posts and having a pulley to adjust the vertical level of the boat.
A device for water motion cushioning has been proposed that uses an extendible tension spring to anchor boats and other objects in various desired positions where the desired effect is smooth ride upon the water surface.
Another approach is provided which uses a plurality of nylon lines, a snaphook for connecting each line to the boat, a counterweight connected to the other end of each line, and hardware for mounting on a plurality of pilings. This approach addresses the vertical motion problem without addressing the impact problem.
Boat docking systems are proposed which provide bumper or shock absorbing capabilities, and which require the a number of poles or flexible rods and which require that the boat fit or be positioned between the poles or rods. Floating dock systems are also used and well known.
Another mooring system includes a multiple degree of freedom coupler interconnecting a floatation section and anchoring section of a dock system. This system also includes a drawbridge, gangway and shoreline mooring section.
Another mooring system uses a cylinder and piston providing for adjustability for the length of the connecting unit and the connecting unit is connected to the mooring structure in a manner that slidably provides for movement with the tide.
Another mooring device uses two shank members, axial protuberances and three integrally connected cross arm members, and a pair of spaced apart cross arms to connect between the boat and a mooring point.
Other approaches for securing a boat or other floating objects, that allow vertical movement of the boat, or floating objects, in response to change in the water level where the boat is connected to at least one vertically extending shaft which extends upwardly above the surface of the water by ring-like floats having split sections so the boat can be connected to the rings and the shaft can be received through the split sections of the rings.
Another mooring device uses a circular plate, a tubular shaft passing through and fixed to the circular plate, with guide rods serving to guide the mooring ring over and past the circular plate for mooring a watercraft to a dock or a floating buoy.
Another mooring apparatus arrangement permits the boat to rise and drop vertically with the tides or wave action but which constrains the boat from lateral movement relative to a fixed dock or pier using a pair cylindrical posts, affixed to the dock or pier, each of which has a carriage assembly comprising a U-shaped collar having rollers to cooperate with the exterior surface of the posts and ride up and down to accommodate the changes in water level. Such a device does not appear to address the problem of impacts with either the pier or the posts of the apparatus.
Another boat mooring apparatus uses a pair of spring wires extending from the dock and over the water to brackets supporting a horizontal roller to be engaged by a boat-mounted latch.
Another vessel mooring device permits vertical movement of boats by a mooring member looped around a support arm.
For general background material, the reader is directed to U.S. Pat. Nos. 3,695,209, 4,110,989, 4,458,620, 4,480,576, 4,488,502, 4,726,313, 4,735,164, 4,887,654, 4,899,680, 4,940,021, 4,979,453, 4,990,029, 5,014,638, 5,044,829, 5,107,785, 5,174,234, 5,184,562, 5,265,553, 5,307,753, 5,341,757, 5,361,716, 5,425,324, 5,493,991, 5,513,592, 5,575,234, 5,588,387, and 5,588,782 each of which is hereby incorporated by reference in its entirety for the material disclosed therein.